The Radioimmunoassay Core provides project investigators with access to validated assays and a skilled pool of technical expertise. The Core performs assays for rat immunoreactive glandular kallikrein, kininogenase activity, functional kininogen, kinins in blood, urine and tissue culture media, kininases, renin concentration and activity, cyclic guanosine monophosphate, cyclic adenosine monophosphate, prostaglandin E2, 6-keto-prostaglandin F1alpha, angiotensin II, atrial natriuretic factor and brain natriuretic peptide. Other assays will be developed and validated as needed to support continuing research projects. The centralized Radioimmunoassay Core helps integrate the various projects by providing assay results that are uniformly and objectively quality- controlled. Centralized use of technical staff and equipment provides better cost control, because duplication of efforts by individual investigators is eliminated. Results of the same assay are directly comparable among the various project investigators because all data are derived from a common method and subject to identical quality-control criteria. In addition, the Radioimmunoassay Core relieves project investigators of the need to maintain analytical methodologies and allows them more time to design and carry out experimental protocols, analyze data, and write manuscripts.